Hypodermic syringes



July 7, 1959 M. L. LOCKHART- 2,893,390

HYPODERMIC 'SYRINGES Filed April 28, 1954 Un ted States liam Matthies,Rutherford, N.J., and Arthur Burton Kettle, Needham, Mass., executors,assignors of onev ffifth each to Edgar H. 'Wilburn' .andRobert W.Matthies Application .April 28,1954, Serial No. 426,122

9 Claims. ;(Cl. 128-218) The present invention :relates to hypodermicsyringes :of the "loaded type :wherein a tubular ampule structure orbarrel carries a single dosage of parenteral liquid medicasment.expellable therefrom through an injective cannula, and may be of theform frequently termed disposable in that they may be discarded afterone use in the hypodermic administration of their contents.

A general object of the present invention is to provide embodiments ofsuch hypodermic syringes which are so constructed with respect to headmeans thereof that sup- .port, or are adapted tosupport, injectivecannula means as to isolateetfectively the head means from containedparenteral liquid by hydraulically-displaceable partition :plug .means.

'A more specific object of the present invention is to provide in suchhypodermic syringes a capacity-reducible liquid compartment loaded withparenteral liquid medica- .ment .efifectively blocked off from contactwith other syringe elements, such as head structure and injectivecannula means that may be supported on the latter, by partition plugmeans hydraulically-displaceable by, initial reduction of the capacityof the liquid-loaded compartment to permit efficient hypodermicadministration of the liquid upon further reduction of the capacity ofthis compartment.

Another =object of the invention is to provide in such hypodermicsyringe structure a rear expelling liquid compartment loaded withparenteral liquid medicament and .an empty head compartment which maycontain sterile gaseous medium, such as air, at atmospheric pressure,separated from each other by partition plug means readily slidableforward by hydraulic pressure of the parenteral "liquid to a position ofcommunication of the compartments permitting efiicient hypodermicadministration of the liquid through the head compartment and outthrough a hollow hypodermic needle connected to the head compartment.

A further object of the present invention is to provide such ahypodermic syringe in a disposable form, preferably made from glass, orthe like, assuring long noncontaminable or non-deteriorating storagelife for contained parenteral liquid medicament effectively housed orisolated'in an elongated barrel chamber by walls of the glass-likematerial and plugs of non-contaminable elastic material at opposite endsof the chamber, one :plug serving as a hydraulic pressure-developing andliquid-expelling piston plug and the other serving as an outlet gateplug which when slid forward hydraulically by action of the piston plugefiiciently permits hypodermic administration of the parenteral liquidby the latter.

Astill further object of the present invention is the provision ofstructural embodiments of the hypodermic device which are readilyconstructed and assembled on an economical mass production basis, whichassure elfitent O I 2,893,390 Patented July 7, 1959 -2 cientnon-deteriorating storage of parenteral liquid medic aments forprolonged periods and which permit elficient hypodermic use andoperation in very simple manners.

Other objects of the invention will in part be obvious and will in partappear hereinafter;

The invention accordingly comprises the features of construction,combinations of elements, and arrangement of parts, which will beexemplified in the constructions hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

Fig. l'is an enlarged axial section, with parts broken away, of anembodiment of the hypodermic syringe of the present invention, showingthe slidable partition plug means partly in section and partly inelevation;

Fig. 2 is an enlarged sectional detail of the head end of the embodimentof the device illustrated in Fig. 1, showing the position of thepartition plug means after hydraulic sliding manipulation thereof andillustrating the manner in which it permits passage of parenteral liquidcontents of the barrel for hypodermic administration of the latter;

Fig. 3 is an end elevation of the partition plug means used in theembodiment illustrated in Figs. 1 and 2;

Fig. 4 is a side elevational view of the partition plug means shown inFig. 3;

Fig. 5 is a sectional view with parts broken away, somewhat similar toFig. 2, of a still further embodiment, ditfering chiefiyfrom thestructure shown in Fig. 2 in the gate plug employed therein andillustrating aspirating action for a show of blood as distinguished fromthe parenteral liquid expulsive action illustrated in Fig, 2;

Fig. 6 is an end elevational view similar to Fig. 3 of the gate plug ofthe 'Fig. 5 embodiment;

Fig. 7 is a side elevational view similar to Fig. 4 of the gate plugillustrated in Figs. 5 and 6;

Fig. 8 is a side elevational view similar to Fig. 4 of a furthermodified form of the gate plugs illustrated in Figs. 1 to 7 incl. andemployable in the syringe structure illustrated in Figs. 1, '2 and 5;and

Fig. 9 is a sectional 'view taken substantially on line 99 of Fig. 8.

It has been proposed, prior to the present invention and thedevelopments of the embodiments hereof, to sup ply parenteral liquidmedicament in loaded hypodermic syringes of the disposable single-dosagetype wherein, during storage and distribution, cannula means thereofwere isolated from contact by the liquid contents. Some such proposalshave employed puncturable or valved diaphragm means for the isolatingfunction but have been uneconomical and diflicult to manufacture andhave not assured, to a desired degree, the isolation desired. Other suchproposals have involved the employment of gaseous medium at elevatedpressures with the diiferential in pressure tending to maintain closedisolating valve means.

Such devices employing gaseous medium at elevated pressures have beenconsidered by some customers to be inadequately free of likelihood ofbreakage with attendant loss of gas pressure causing opening of thevalve means. Also, possible storage of certain parenteral liquidmedicaments to assure against contamination and deterioration thereoffor unusually long periods, e.g., for a number of years, has led someretailers to demand packaging in glass-like material or glass capsulesand bottles suitably stopper-ed by rubber and like non-contaminatingmaterials; others have demanded such type of packaging for certainmedicaments, such as poliomyelitis prophylactics. These and otherproblems of the prior art and demands of the trade have been eflicientlysolved and satisfied by the present invention.

Referring to the drawings, in which like numerals identify similar partsthroughout, and more specifically, to

. Figs. l'to 4 inclusive, it will be seen that an embodiment of thepresent invention may comprise a loaded hypodermic syringe 650 of thesingle dosage, disposable type, including a tubular ample structure 651,cannula means 52, and a protective cover 253 for the latter. The tubularampule structure 651 of the Figs. 1 to 4 inclusive embodiment includesside wall means in the form of a tubular barrel, preferably formed oftransparent glass, having head end wall means 655 in the form of frontend structure, and back end wall means which may be the form of a pistonplug 57 slidably' fitted in the open back end of the barrel, together todefine an internal chamber 59 loaded with a quantity or body 60 ofparenteral liquid medicament. I

Figs. 1 to 9 inclusive illustrate embodiments of the present inventionwherein the partition plugmeans, in

the form of a gate plug, is not completely expelled into the headcompartment for communicating the latter with the liquid-containing rearcompartment. As illustrated in Figs. 1 and 2, barrel 651 may have a headend struc-i into the inturned tip end 566 of the bulbous head, as ismore clearly illustrated in Fig. 2. As is best seen in Fig. 4, gate plug765 preferably is in the form of an elongated cylindrical member havinga shank 98 provided with a solid tip portion 99 and a rear portion 100which has at least one longitudinally-extending fluid way but preferablytwo of the latter in the form of a pair of diametrically-oppositegrooves 101, 101. The gate plug 765 also is preferably, though notnecessarily, provided with an enlarged back end head 102, through ilarin some respects to gate plug 765 of Figs. 1 and 2, may be employed inthe hypodermic syringe structure 650. It is usual to have the needleinner end 68 extend appreciably into the head compartment 464 beyond thesilica blob 193 to avoid necessity for meticulous placement of theneedle inner end in the blob wall while assuring that the bore of theneedle will not be blocked off by the silica material when fused betweenthe needle and the bulbous head 461. This, of course, limits the spacein which a slidable gate plug of the type illustrated in Figs. 1 and 2may operate since the tip end of the gate plug must not block off theneedle bore when thrust forward. As illustrated in Figs. 5, 6 and 7,slidable gate plug 865 is of such structure as to accommodate theserequirements. a

The gate plug 865 is in the form .of a cylindrical .body 198 having acylindrical tip portion 199 which is provided with an axially-extendingsocket-103 of a diameter appreciably larger than the outer diameter ofthe needle inner end 68 to form a skirt for loosely housing the latter.A projection 104 on the tip end 199 is adapted to abut the silica hub193 if need be so that the inner end or the bottom of the socket 103will not contact the needle inner end 68. Stop projection 104 alsoassures spacing of the front edge 105 of the skirt formed by thesocketed tip 199 from the silica hub to permit free aspirated flow backthrough groove 201 via compartment 464 from the needle bore into socket103 and between skirt edge 105 and the silica hub 193, and freeexpulsive flow in the reverse direction. The gate plug 865 is alsopreferably provided with only one, relatively large,longitudinally-extending, side groove 201, which provides communicationbetween the liquid-containing rear compartment 59 and the headcompartment 464 and in which flowing blood may be readily observedthrough transparent neck 362. The rear-most flow-blocking position ofthe gate plug 865 is indicated in dotted lines at 106 in Fig. 5 and itsforward flow-permitting position is shown in full lines therein.

' Also, Fig. 5 illustrates by arrows aspirating action of the which theflow ways or grooves 101, 101 extend. Initially, the solid cylindricaltip portion 99 of the slidable gate plug 765 is located in the passageseat 363 intervening the rear compartment 59 and the head compartment 9464 so as to isolate those compartments from each other H in a fluidflow-preventing manner. This is the rear-most flow-blocking position ofthe gate plug, as illustrated in Fig. 1.

When hydraulic pressure is applied to the gate plug 765 of the Fig. 1structure by reduction of the internal volumetric capacity of the rearcompartment 59 upon forward thrust of the piston plug 57, the gate plugis slid forward to a flow-permitting position illustrated in Fig. 2. [nthis position, the grooves 101, 101 extend from points back of the innerend of the partition seat 363 to points forward thereof in the emptyhead compartment464 so as to provide flow-ways allowing the parenteralliquid medicament 60 to be expelled from the rear compartment 59 withfurther forward thrust of thepiston plug 57, out through the headcompartment and thence through the bore of the injective needle 52, asillustrated by the arrows in Fig. 1. Of course, the longitudinal grooves101, 101 also provide reverse aspirating ways when the piston plug 7 isin its forward flow-permitting position,

illustrated in Fig. 2, to test for a show of blood and flow of thelatter will be immediately adjacent the inside wall of peck 362 as it isconducted back through the longitudinal grooves for ready observation.

As illustrated in Figs. 5, 6 and 7, a gate 9 .1. .3

syringe 650 when equipped with the gate plug 865 after the latter hasbeen hydraulically thrust forward to its full line position.

In the Figs. 1 to 4 inclusive and 5 to 7 inclusive embodiments, thelight-transmitting or transparent head end structure 655 provideseflicient blood telltale means since flow of blood is diverted laterallyto adjacent the inner walls of the transparent bulbous head 461 and theneck 362 for ready observation of flow in the grooves 101, 101 and 201.Also, the skirt provided by the socketed tip 199 of gate plug 865 formsflow diverting means to assure blood flow laterally to adjacent theinner wall of the transparent bulbous head 461. Of course, the tip ofgate plug 765 may be socketed for a like purpose.

As illustrated in Figs. 8 and 9, a slidable gate plug 965 of the typeillustrated in Figs. 1 and 2 may have its flow way provided by an axialbore 107 extending from the back end or the top of the head 202 to tipportion 99 and a side notch 108 communicating between the exteriorsurface of the shank 198 and the bore. If desired, tip portion 99 ofgate plug 965 may also be socketed to a limited degree in the manner ofsocketing tip portion 199 of gate plug 865 for a similar purpose.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efiiciently attained and,since certain changes may be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown'in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense. o

It is also to be understood that the following claims are intended tocover all of the generic and, specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of lanuag rm h e said to tail therebetween.

parenteral liquid rear'compartment, ap'iston plug slidably 'fittedinsaid barrel'and'closingotfitsback end, said front end structurecomprising 'a head having cannula-support ing means and aheadcompartment with which *the -bore of an injecting cannula communicates"when supported on said head, means forming a constricted passage ofcertain length between said compartments to serve as a gate plug seat,and a gate plug slidably fitted in said seat in a rearmost flow-blockingposition and there cooperating with said piston plug in confining insaid rear compartment a body of parenteral liquid medicament, said gateplug being substantially longer than said seat with a flow way extendingfrom the vicinity of its back end forward short of its head end todefine a way-equipped back end section and a head end section with thelatter blocking flow through said seat when said head end section islocated in said seat, said gate plug being slidable forwardhydraulically in said seat passage when the internal capacity of therear compartment is reduced by forward thrust of said piston plug tolocate said way-equipped back end section in said seat passage with theway permitting flow of parenteral liquid from the barrel rearcompartment through the head compartment.

2. A hypodermic syringe structure comprising, in combination; anelongated tubular barrel of substantially rigid, light-transmittingmaterial having an open back end and a front end structure definingtherebetween a parenteral liquid compartment, said front end structureincluding a relatively small hollow head having an outlet and anintervening neck provided with a communicating passage forming a gateplug seat of certain length, said front end structure having tip meansfor support of an injecting cannula with the bore of the latter incommunication with the outlet; a piston plug of elastic materialslidably fitted in the back end of said barrel; a gate plug of elasticmaterial slidably fitted in said seat in a rear-most position blockingfiuid flow through the seat passage, said gate plug being an elongatedgenerally cylindrical element having a front end section and a back endsection with the front end section effectively blocking fluid flowthrough the seat passage when located in the latter, the back endsection of said gate plug having a longituindal way longer than saidseat to permit flow through the seat passage when said gate plug isthrust forward; and a body of parenteral liquid confined in said barrelcompartment between said plugs to apply hydraulic pressure to said gateplug and slide it forward to position the back end section of the latterin said seat when said piston plug is thrust forward initially to reducethe capacity of the barrel compartment, said piston plug thereafter infurther forward thrust applying expelling pressure to the liquid in thebarrel compartment to force it from the latter through the seat passageby way of the gate plug way and then through the outlet passage forhypodermic administration through such cannula.

3. The hypodermic syringe structure as defined in claim 2 characterizedby an injecting cannula being sealed to said tip means with the cannulabore communicating through the latter with the outlet of said front endstructure, said hollow head having at least a portion integral with saidbarrel to be generally transparent for facilitating observation of anaspirated show of blood in the hollow head.

4. A disposable hypodermic syringe comprising, in combination, anelongated cylindrical barrel of transparent glass-like material havingan open back end and an integral head end structure definingtherebetween a cylindrical parenteral liquid chamber, said head endstructure providing a neck for said barrel having an elongated passagesubstantially circular in cross-section and formingf agate plug'se'at, agate plug of elastic material slidably fitted in said seat in an initialflow-blocking position, a piston plug of elastic material slidablymounted in and closing off-the back end of said barrel chamber with abody of parenteral liquid confined'in the latter between said plugs,said head end structure having a relatively small hollow head beyondsaid neck with which said seat'passage communicates when unblocked andproviding'an outlet passage of a lateral dimension greater than that ofthe seat passage, an injecting can'- nula sealed to said hollow headwith its bore in communication with the latter and isolated from theparenteral liquid by said gate plug, and an elongated protective coverover said cannula and removably mounted to said head while beingtelescopically receivable in said barrel chamber for forward thrust ofsaid piston plug; said gate plug being an elongated, substantiallycylindrical body appreciably longer than said seat and having a solidfront end section slidably seated initially in said seat to block flowthrough the seat passage, said gate plug also having a rear end sectioninitially extending into said chamber and having alongitudinally-extending way longer than the seat passage through whichparenteral liquid may flow when said rear end section is moved forwardinto said seat, said gate plug being slidable forward hydraulically toflow-permitting position with forward thrust of said piston plug toreplace in said seat the front end section of said gate plug with itsrear end section.

5. The hypodermic syringe as defined in claim 4 characterized by saidgate plug being provided with its longitudinally-extending way in theform of a side groove in which aspirated flow of blood may be readilyobserved through the adjacent side wall portion of said transparentneck.

6. The hypodermic syringe as defined in claim 4 characterized by saidhollow head having a front wall, said cannula having its back endprojecting through and beyond and sealed in said front wall of saidhollow head, said gate plug having a recess of a lateral dimen siongreater than the lateral dimension of said projecting back end of saidcannula with the bottom of the recess being stopped short of thiscannula back end when said gate plug is hydraulically moved forward tothe flow-permitting position.

7. The hypodermic syringe as defined in claim 6 characterized byprojecting means on said gate plug to assure stopping of the latter withthe recess bottom short of the cannula back end.

8. The hypodermic syringe as defined in claim 7 characterized by saidprojecting means being on the front of the front end section to abutsaid hollow head front wall.

9. A hypodermic syringe structure comprising, in combination, meansproviding a front end structure, means providing an elongated tubularbarrel located behind said front end structure and defining a parenteralliquid chamber, a piston plug slidably fitted in the back end of saidbarrel and closing off the back end of said chamber, said front endstructure comprising head means defining therein in front of said barrelchamber a communicating space, a single-ended injecting cannula havingits shank carried by said head means with its bore in communication withthe head space, means between said head means and the front end of saidbarrel defining a communicating passage between the chamber and headspace, and a gate plug slidably fitted in said passage in rear-mostflow-blocking position and there cooperating with said piston plug inconfining in said chamber a body of parenteral liquid medicament, saidgate plug being substantially longer than the communicating passage witha flow way extending from the vicinity of its back end forward short ofits front end to define a wayequipped back end section and a head endsection with -the 'latter located in the passage and blocking flowtherethrough, said gate plug being slidable hydraulically forward in thepassage when the internal capacity of the chamber is reduced by forwardthrust of said piston plug a Y References Cited in the 'file' of thispatent UNITEDfSTATES PATENTS Gupti11 Nov, 25; 1890 I Sellar Sept. 16,1919 Brown Apr; 17, 1951 Brown Apr. 1, 1952 Lockhart Apr. 28, 1953 HuberSept. 14, 1954 Lockhart Nov. 30, 1954

